( | x | − | 20 | ) | ÷ | 3 | = | 2 | ÷ | ( | x | − | 20 | − | 40 | ) |
方程两边同时乘以: | ( | x | − | 20 | − | 40 | ) |
( | x | − | 20 | ) | ÷ | 3 | × | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | ÷ | 3 | × | ( | x | − | 20 | − | 40 | ) | − | 20 | ÷ | 3 | × | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | × | 1 3 | ( | x | − | 20 | − | 40 | ) | − | 20 3 | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | × | 1 3 | x | − | x | × | 1 3 | × | 20 | − | x | × | 1 3 | × | 40 | − | 20 3 | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | × | 1 3 | x | − | x | × | 20 3 | − | x | × | 40 3 | − | 20 3 | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | × | 1 3 | x | − | 20 | x | − | 20 3 | ( | x | − | 20 | − | 40 | ) | = | 2 |
x | × | 1 3 | x | − | 20 | x | − | 20 3 | x | + | 20 3 | × | 20 | + | 20 3 | × | 40 | = | 2 |
x | × | 1 3 | x | − | 20 | x | − | 20 3 | x | + | 400 3 | + | 800 3 | = | 2 |
x | × | 1 3 | x | − | 80 3 | x | + | 400 | = | 2 |